A router/switch performs inbound processing that receives a packet from the side of an access network to which a user device is connected, and outbound processing that transmits a packet to the side of the access network (concentrates the access network and assumes a position to connect a core network). A packet transfer processing device generates transfer destination information based on the header information of a received packet and route information acquired in advance and transmits a packet having a header including the transfer destination information. Such a packet transfer processing device conventionally includes a dedicated inbound processing unit and a dedicated outbound processing unit and implements both processes.
FIG. 19 is a block diagram showing an example of the arrangement of a conventional general packet transfer processing device. A packet transfer processing device 100 includes a dedicated inbound processing unit 101 and a dedicated outbound processing unit 102. Referring to FIG. 19, reference numeral 103 denotes a reception terminal that receives a packet from an access network; 104, a reception terminal that receives a packet from a core network; 105, a transmission terminal that transmits a packet to the core network; and 106, a transmission terminal that transmits a packet to the access network. Such a packet transfer processing device is disclosed in, for example, literature “Osamu Ishida, Koichiro Seto, “10 Gbit Ethernet® Textbook”, Impress R&D, p. 76, 2005”.
Inbound processing that receives a packet from the access network and transmits it to the core network is performed by the dedicated inbound processing unit 101, and outbound processing that receives a packet from the core network and transmits it to the access network is performed by the dedicated outbound processing unit 102. Hence, the two dedicated processing units need to be operated always even when the amount of packets (traffic volume) to be processed is small. For this reason, the packet transfer processing device 100 always consumes power for the two dedicated processing units even if the performance has a margin for the processing amount.